Conventionally, unit management and communication process are performed in a communication unit. As the result of adoption of broadband communication and ALL IP (Internet Protocol) in recent years, it is necessary to perform complicated manipulation and many processes for network, load imposed on a control unit of the communication unit has become heavy. It should be noted that ALL IP means an environment that all the units are connected with an IP network.
In this way, the load on the unit has become heavy with rapid development of a network infrastructure, so that a network configuration itself has become excessively complicated because of diversification of use of the network.
In order to solve the above-mentioned problem, expectation to a new generation network is increasing. At this time, it is required to make it possible to flexibly control the network unit from a control plane, for reconfiguration of architecture and expansion of variety from a clean slate. For this purpose, a mechanism to freely control a network interface from a controller would be required.
At present, as one of the mechanisms to control the network interface from the controller, a mechanism called an “open flow (OpenFlow)” is considered. It should be noted that the open flow (OpenFlow) is an architecture which is prescribed in “The OpenFlow Switch Consortium” (Non-Patent Literature 1).
As one of methods to reinforce the band of a communication line, a method called “Link Aggregation (LA)” is known in which a plurality of physical communication lines between network units are virtually bundled to handle as a single thick communication line.
In order to utilize the characteristics of the open flow (OpenFlow) and to control a flow flexibly, it is necessary to implement both of a link aggregation group (LAG) and a physical port to which the link aggregation group belongs, so as to be a searchable object.
However, in a conventional management, the link aggregation group itself is manipulated as a link aggregation group interface and the physical port for the group is hidden. In this case, a management interface in the open flow (OpenFlow) is the link aggregation group interface. Therefore, the physical port which belongs to the link aggregation group is excluded from a management object in the open flow (OpenFlow).
In the open flow (OpenFlow), in a case of search of a candidacy of the management interface, when the link aggregation group is used as the search object, the physical port cannot be specified as the interface of the search object.
On the contrary, in the open flow (OpenFlow), when the physical port to which the link aggregation group belongs is specified as the search object, the link aggregation group interface cannot be specified as the search object.
It should be noted that as the related technique, a communication system, a packet transmission control method using the same, and a program for the same are disclosed in Japanese Patent Publication (JP 2007-180891A) (Patent Literature 1).